In the manufacture of semiconductor integrated circuits (IC), dielectric materials such as silicon dioxide (SiO2), silicon nitride (Si3N4), and silicon oxynitride (SiON) have been widely used as insulators for transistor gates. As IC device geometry shrinks, gate dielectric layers have become progressively thinner. To maintain adequate breakdown voltage at very small thickness (≦10 nm), high dielectric constant (high-k) materials, defined as materials where k is greater than about 4.1 (the k of silicon dioxide) can be used as the insulating layer in the transistor gate structure and the barrier layer in deep trench capacitors. The latest and most promising high-k materials are metal oxides such as Al2O3, HfO2, ZrO2, and mixtures thereof, and metal silicates such as HfSixOy, ZrSixOy, and mixtures thereof. In some instances, nitrogen may be incorporated into these metal oxides and metal silicates high-k materials.
Semiconductor Process Chambers such as Chemical Vapor Deposition (CVD) chambers, and specifically Atomic Layer Deposition (ALD) chambers, which are employed for the deposition of high k films, often are exposed to highly corrosive gases during processing of semiconductor components or during periodic cleaning to remove accumulation of deposition residues from the interior surfaces. Among the highly corrosive gases employed for processing and cleaning are the halogen-containing agents, Cl2, HCl, BCl3, NF3, F2, HF and/or a combination of BCl3/NF3. Cleaning high-k ALD/CVD chambers using highly corrosive halogen-based chemistries activated by in situ plasma, remote plasma, and/or thermal heating have been demonstrated as being very effective. However, because BCl3 or BCl3/NF3 in situ plasmas are extremely aggressive, these halogen-based in situ plasmas, for example, not only remove high-k deposition residues from the reactor surfaces they also etch and corrode the internal components and surfaces of the ALD/CVD deposition chambers.
The following patents and articles are illustrative of processes for imparting resistance to corrosion and etching of ALD and CVD reactors which are subjected to halogen gases during processing of semiconductor components and from cleaning from time to time.
WO 02/054454 A2, and U.S. Pat. No. 6,537,429 B2, disclose the incorporation or corrosion resistant components in semiconductor processing equipment such as a plasma chamber. To prevent erosion caused by the corrosive effects of plasma chamber gases on walls, electrodes, supports, etc. commonly constructed of aluminum and aluminum alloys, diamond-like coatings are applied to such interior surfaces.
U.S. Pat. No. 6,533,910 B2 and WO 02/053794 A1 disclose corrosion resistant components for semiconductor processing equipment based upon carbonitride coatings. These coatings are deposited on the surface of the processing equipment, such surfaces include ceramic, stainless steel, refractory and the like as well as those coated with alumina, SiC, of Si3N4.
WO 02/053797 A1 discloses a method for providing corrosion resistance to metal, ceramic and polymer surfaces interior components of semiconductor processing apparatus including parts of a plasma reactor chamber. Hard carbon intermediate layers are incorporated into chamber surfaces which hard carbon intermediates include fullerenes such as C60 and C70 etc (buckyballs or buckmisterfullerenes), diamond, carbides, carbonitrides, borides and the like.
EP 1,026,281 A2, discloses an anti-corrosion member based upon a support having a film thereon incorporating a main crystal phase of AlF3. Such film affords corrosion and erosion resistance to a base member of a metal in which aluminum is included, ceramics in which aluminum is included and so forth when heated to elevated temperatures in the presence of corrosive fluorine compounds, e.g., WF6.
U.S. Pat. No. 2003/0159657 A1 and WO 03/001559 A1 disclose the application of a monolithic ceramic workpiece for a plasma reactor chamber formed from a mixture of yttrium aluminum perovskite and yttrium aluminum garnet. Such mixture acts to prevent erosion of the internal chamber components which are susceptible to corrosion and wear by fluorine processing gases.
WO 03/080892 A1, discloses components for semiconductor materials which are subjected to erosive and corrosive plasma environments. Such components are based upon ceramic coatings comprised of at least one oxide, nitride, boride, carbide and/or fluorides of strontium, lanthanum and dysprosium or a nitride, boride, carbide or fluoride of hafnium.
U.S. 6,613,442 B2, and WO 2004/003962 A2 disclose various methods to protect semiconductor processing chambers by employing various binary metal compounds such as aluminum nitride, boron nitride, and in particular, boron nitride/yttrium oxides and cerium oxides.